[turbofan] Introduce optional Float64Min and Float64Max machine operators.

src/compiler/common-operator-reducer.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_COMMON_OPERATOR_REDUCER_H_
 #define V8_COMPILER_COMMON_OPERATOR_REDUCER_H_
 
 #include "src/compiler/graph-reducer.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
+// Forward declarations.
+class CommonOperatorBuilder;
+class Graph;
+class JSGraph;
+class MachineOperatorBuilder;
+
+
 // Performs strength reduction on nodes that have common operators.
 class CommonOperatorReducer FINAL : public Reducer {
  public:
-  CommonOperatorReducer() {}
+  explicit CommonOperatorReducer(JSGraph* jsgraph) : jsgraph_(jsgraph) {}
   ~CommonOperatorReducer() FINAL {}
 
   Reduction Reduce(Node* node) FINAL;
+
+ private:
+  Reduction ReduceEffectPhi(Node* node);
+  Reduction ReducePhi(Node* node);
+  Reduction ReduceSelect(Node* node);
+
+  CommonOperatorBuilder* common() const;
+  Graph* graph() const;
+  JSGraph* jsgraph() const { return jsgraph_; }
+  MachineOperatorBuilder* machine() const;
+
+  JSGraph* const jsgraph_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_COMMON_OPERATOR_REDUCER_H_